BRUSSELS, Jan 17 (Reuters) - The European Union will need a valid reason to extend the deadline for Britain’s exit from the EU beyond March 29th if London were to ask for it, the spokesman for the European Commission Margaritis Schinas said on Thursday.

“We have not received such a request from the UK for an extension,” Schinas told a regular news briefing.

“Should there be a UK request to extend, this will be decided unanimously by the 27 and of course the request will have to set out the reasons for such an extension,” he said. (Reporting By Jan Strupczewski and Francesco Guarascio)